Process for production of heteroaryl-type boron compounds with iridium catalyst

ABSTRACT

The present invention provides an economically and industrially superior simple process that enables the selective production of an aromatic heterocyclic monoboron compound and aromatic heterocyclic diboron compound at a satisfactory yield and in a desired ratio by reacting an aromatic heterocyclic compound and a boron compound in a single step under mild conditions while changing only the charged ratios of the raw materials. 
     The present invention provides a production process of a heteroaryl mono- or diboron compound comprising an aromatic heterocyclic compound and a boron compound in the form of bis(pinacolate)diboron or pinacolate diborane in the presence of a iridium-containing catalyst and a ligand such as a bipyridyl ligand.

TECHNICAL FIELD

The present invention relates to a production process of an aromaticheterocyclic boron compound that uses an iridium-containing catalyst. Anaromatic heterocyclic boron compound produced according to the presentinvention can be used as a reaction substrate when producing biarylderivatives and polyaryl derivatives that are useful as pharmaceuticaland agricultural chemical intermediates as well as functional organicmaterials.

BACKGROUND ART

Various processes have been proposed in the prior art for boronation ofaromatic hydrocarbons. For example, processes are known forlithionation, halogenation or boronation after converting to a trifurateof a benzene ring, examples of which include (1) a process using arylhalide or aryl trifurate and pinacol diboron (P. Rocca et al., J. Org.Chem., 58, 7832, 1993), (2) a process involving reaction with boricester following lithionation of an aromatic ring, and (3) a processinvolving reaction with boric ester following reaction of aryl halidewith magnesium (A. R. Martin, Y. Yang, Acta. Chem. Scand., 47, 221,1993).

In addition, known examples of direct boronation of benzene include (4)a process that uses a boron halide (T. R. Kelly et al., TetrahedronLett., 35, 7621 (1994), P. D. Hobbs et al., J. Chem. Soc. Chem. Commun.,923 (1996), T. R. Hoye, M. Chen, J. Org. Chem., 61, 7940 (1996)), (5) aprocess that uses an Ir-based catalyst (Iverson, C. N., Smith, M. R.,III. J. Am. Chem. Soc., 121, 7696 (1999)), (6) a process that uses anRe-based catalyst (Chen. H., Hartwig, J. F., Agnew. Chem. Int. Ed., 38,3391 (1999)), (7) a process that uses an Rh-based catalyst (Chen, H.,Hartwig, J. F., Science, 287, 1995 (2000), Cho, J. Y., Iverson, C. N.,Smith, M. R., III. J. Am. Chem. Soc., 122, 12868 (2000), Tse, M. K.,Cho, J. Y., Smith, M. R., III. Org. Lett., 3, 2831 (2001), Shimada, S.,Batsanov, A. S., Howard, J. A. K, Marder, T. B., Angew. Chem. Int. Ed.,40, 2168 (2001)), and (8) a process that uses an Ir-based catalyst (Cho,J. Y., Tse, M. K., Holmes, Science, 295, 305 (2002), Ishiyama, T.,Takagi, J., Ishida, K., Miyaura, N., Anastasi, N. R., Hartwig, J. F., J.Am. Chem. Soc., 124, 390 (2002)).

However, there are few examples of boronation reactions of aromaticheterocyclic compounds, with the only known example being (9) a processin which silver acetate is allowed to act on indole followed by reactionwith borane followed additionally by hydrolysis (K. Kamiyama, T.Watanabe, M. Uemura, J. Org. Chem., 61, 1375 (1996)).

Although the processes (1) through (9) are known as examples ofboronation of an aromatic ring as mentioned above, these examples of theprior art have the following disadvantages. The processes of (1) through(3) have a large number of steps for carrying out lithionation,halogenation or trifluorination of a benzene ring, thereby resulting inproblems with industrial production. Moreover, process (1) only uses oneof the two borons of the diboron used, thereby making it uneconomical,while processes (2) and (3) are subjected to considerable restrictionson the functional groups of the substrate used due to going through ahighly reactive intermediate. Process (4) has the disadvantages of harshreaction conditions, low yield and the formation of isomerism in thecase of substrates having functional groups. In the processes of (5)through (7), the catalyst is difficult to acquire while also having theproblem of requiring harsh reaction conditions. In process (8), althoughthere are some processes that enable boronation of a benzene ring totake place with high yield and in a single step, there are no knownapplication examples for the aromatic heterocyclic ring. In the processof (9) involving application of boronation to a complex ring, there isthe disadvantage of having to react borane, which is associated with therisk of toxicity and explosiveness, after allowing harmful silveracetate to act on indole. In consideration of these circumstances, thereis a need for the development of a novel boronation reaction foraromatic complex rings that is able to overcome the aforementionedproblems.

DISCLOSURE OF THE INVENTION

As a result of conducting extensive studies to resolve theaforementioned problems, the inventors of the present inventiondeveloped a novel boronation of an aromatic heterocyclic compound, andestablished a production process of extremely useful aromaticheterocyclic boron compounds that uses an easily prepared iridiumcatalyst and bipyridine derivative as ligands, allows the reaction toproceed efficiently under mild conditions, produces few byproducts, andenables mono- and/or diboronation of an aromatic heterocyclic compoundin a single step, thereby leading to completion of the presentinvention.

Namely, a first aspect of the present invention relates to a productionprocess of a heteroaryl boron compound represented with general formula(V) or (VI):

(wherein, X, Y, Z, R¹ and R² are the same as defined below) comprising:reacting an aromatic heterocyclic compound represented with thefollowing general formula (I):

(wherein, X represents an oxygen atom, sulfur atom or an imino groupwhich may have a substituent, Y and Z may be the same or different andrespectively represent —CH═ or —N═, R¹ and R² may be the same ordifferent and respectively represent a hydrogen atom, linear or branchedC₁₋₈ alkyl group, linear or branched C₁₋₈ alkoxy group, nitro group,cyano group, halogenated C₁₋₈ alkyl group, halogen atom, carbamoylgroup, C₁₋₈ acyl group, C₁₋₈ alkoxycarbonyl group, amino group which mayhave a substituent, or the following general formula (II) in which R¹and R² are adjacent and form a ring:

(wherein, R³ represents a hydrogen atom, a linear or branched C₁₋₈ alkylgroup, a linear or branched C₁₋₈ alkoxy group, nitro group, cyano group,halogenated C₁₋₈ alkyl group, halogen atom, carbamoyl group, C₁₋₈ acylgroup, C₁₋₈ alkoxycarbonyl group or amino group that may have asubstituent)) with a boron compound represented with the followinggeneral formula (III) or (IV):

in the presence of an iridium-containing catalyst and a ligand.

A second aspect of the present invention relates to a production processof a heteroaryl boron compound represented with general formula (VIII)or (IX):

(wherein, u, v, w, R⁴ and R⁵ are the same as defined below) comprising:reacting an aromatic heterocyclic compound represented with thefollowing general formula (VII):

(wherein, u, v and w may be the same or different and respectivelyrepresent —CH═ or —N═, and R⁴ and R⁵ may be the same or different andrespectively represent a hydrogen atom, linear or branched C₁₋₈ alkylgroup, linear or branched C₁₋₈ alkoxy group, nitro group, cyano group,halogenated C₁₋₈ alkyl group, halogen atom, carbamoyl group, C₁₋₈ acylgroup, C₁₋₈ alkoxycarbonyl group, amino group which may have asubstituent, or the following general formula (II) in which R⁴ and R⁵are adjacent and form a ring:

(wherein, R³ represents a hydrogen atom, a linear or branched C₁₋₈ alkylgroup, linear or branched C₁₋₈ alkoxy group, nitro group, cyano group,halogenated C₁₋₈ alkyl group, halogen atom, carbamoyl group, C₁₋₈ acylgroup, C₁₋₈ alkoxycarbonyl group or amino group that may have asubstituent)) with a boron compound represented with the followinggeneral formula (III) or (IV):

in the presence of an iridium-containing catalyst and a ligand.

BEST MODE FOR CARRYING OUT THE INVENTION

The following provides a detailed explanation of the present invention.Any aromatic heterocyclic compound can be used for the aromaticheterocyclic compound used as a raw material in the present inventionprovided it has at least one aromatic sp²C—H bond. Specific examples ofaromatic heterocyclic compound (I) or (VII) include furan; alkyl furanssuch as 2-methyl furan, 3-methyl furan, 2-ethyl furan, 3-isopropylfuran, 2-isopropyl furan, 2-butyl furan, 3-butyl furan, 2-isobutylfuran, 3-isobutyl furan, 3,4-dimethyl furan, 3-butyl-4-methyl furan,2,5-dimethyl furan, 3,4-diisopropyl furan, 2-isopropyl-3-methyl furan,3-butyl-4-isopropyl furan and 2-butyl-5-isopropyl furan; alkoxy furanssuch as 3-methoxy furan, 2-ethoxy furan, 3-butoxy furan, 2-isopropoxyfuran, 2-methoxy furan and 3-ethoxy furan; nitrofurans such as3-nitrofuran and 2-nitrofuran; cyanofurans such as 3-cyanofuran and2-cyanofuran; halofurans such as 2-chlorofuran, 3-chlorofuran,4-chlorofuran and 2-bromofuran; halogenated alkyl furans such as3-trifluoromethyl furan and 2-trifluoromethyl furan; carbamoyl furanssuch as 3-carbamoyl furan, 2-dimethylcarbamoyl furan and4-dimethylcarbamoyl furan; acyl furans such as 3-acetyl furan, 2-acetylfuran and 3-butanoyl furan; alkoxycarbonyl furans such as3-methoxycarbonyl furan, 2-methoxycarbonyl furan and 3-ethoxycarbonylfuran; N-substituted amino furans such as 2-amino furan, 3-amino furan,2-dimethylamino furan and 3-dimethylamino furan; alkyl halofurans suchas 4-chloro-3-butyl furan and 4-methyl-2-chlorofuran; alkoxyalkyl furanssuch as 2-methoxy-3-methyl furan, 2-methoxy-4-methyl furan and2-ethoxy-5-methyl furan; cyano-substituted chlorofurans such as3-chloro-2-cyanofuran, 3-chloro-4-cyanofuran, 3-chloro-5-cyanofuran,4-chloro-2-cyanofuran and 4-chloro-3-cyanofuran; nitro-substitutedchlorofurans such as 3-chloro-2-nitrofuran, 3-chloro-4-nitrofuran,3-chloro-5-nitrofuran, 4-chloro-2-nitrofuran and 4-chloro-3-nitrofuran;aminochlorofurans such as 3-chloro-4-amino furan,3-chloro-5-dimethylamino furan, 4-chloro-2-dimethylamino furan and4-chloro-3-dimethylamino furan; carbamoylchlorofurans such as3-chloro-4-carbamoyl furan, 3-chloro-5-dimethylcarbamoyl furan,4-chloro-2-dimethylcarbamoyl furan and 4-chloro-3-dimethylcarbamoylfuran; halogenated alkyl furans such as 4-chloro-2-trifluoromethyl furanand 4-chloro-3-trifluoromethyl furan; benzofuran; alkyl benzofurans suchas 6-methyl benzofuran, 4-methyl benzofuran, 5-methyl benzofuran,4-isopropyl benzofuran, 2-isopropyl benzofuran, 6-isopropyl benzofuran,3-isobutyl benzofuran, 5,6-dimethyl benzofuran, 4-butyl-6-methylbenzofuran, 2,5-dimethyl benzofuran, 3,4-diisopropyl benzofuran,4-isopropyl-5-methyl benzofuran, 4-butyl-6-isopropyl benzofuran and2-butyl-5-isopropyl benzofuran; alkoxy benzofurans such as 4-methoxybenzofuran, 4-ethoxy benzofuran, 5-butoxy benzofuran, 6-isopropoxybenzofuran, 5-methoxy benzofuran, 6-ethoxy benzofuran and 2-methoxybenzofuran; nitrobenzofurans such as 4-nitrobenzofuran and5-nitrobenzofuran; cyanobenzofurans such as 4-cyanobenzofuran and5-cyanobenzofuran; halobenzofurans such as 4-chlorobenzofuran,5-chlorobenzofuran, 6-chlorobenzofuran and 4-bromobenzofuran;halogenated alkyl benzofurans such as 4-trifluoromethyl benzofuran and5-trifluoromethyl benzofuran; carbamoyl benzofurans such as 4-carbamoylbenzofuran, 5-dimethylcarbamoyl benzofuran and 6-dimethylcarbamoylbenzofuran; acyl benzofurans such as 4-acetyl benzofuran, 5-acetylbenzofuran and 6-butanoyl benzofuran; alkoxycarbonyl benzofurans such as4-methoxycarbonyl benzofuran, 5-methoxycarbonyl benzofuran and6-ethoxycarbonyl benzofuran; N-substituted amino benzofurans such as4-amino benzofuran, 5-amino benzofuran, 6-dimethylamino benzofuran and4-dimethylamino benzofuran; alkyl halobenzofurans such as4-chloro-5-butyl benzofuran and 4-methyl-6-chlorobenzofuran; alkoxyalkylbenzofurans such as 2-methoxy-4-methyl benzofuran, 2-methoxy-5-methylbenzofuran and 2-ethoxy-5-methyl benzofuran; halocyanobenzothiophen suchas 4-chloro-6-cyanobenzofuran; thiophene; alkyl thiophenes such as3-methyl thiophene, 4-methyl thiophene, 5-methyl thiophene, 3-isopropylthiophene, 2-isopropyl thiophene, 4-isopropyl thiophene, 5-isopropylthiophene, 2-isopropyl thiophene, 3-isobutyl thiophene, 3,4-dimethylthiophene, 3-butyl-4-methyl thiophene, 2,5-dimethyl thiophene,3,4-diisopropyl thiophene, 2-isopropyl-3-methyl thiophene,3-butyl-4-isopropyl thiophene and 2-butyl-5-isopropyl thiophene; alkoxythiophenes such as 3-methoxy thiophene, 2-ethoxy thiophene, 3-butoxythiophene, 2-isopropoxy thiophene, 2-methoxythiophene, 3-ethoxythiopheneand 2-methoxy thiophene; nitrothiophenes such as 3-nitrothiophene and2-nitrothiophene; cyanothiophenes such as 3-cyanothiophene and2-cyanothiophene; halothiophenes such as 2-chlorothiophene,3-chlorothiophene, 4-chlorothiophene and 2-bromothiophene; halogenatedalkyl thiophenes such as 3-trifluoromethyl thiophene and2-trifluoromethyl thiophene; carbamoyl thiophenes such as 3-carbamoylthiophene, 2-dimethylcarbamoyl thiophene and 4-dimethylcarbamoylthiophene; acyl thiophenes such as 3-acetyl thiophene, 4-acetylthiophene and 3-butanoyl thiophene; alkoxycarbonyl thiophenes such as3-methoxycarbonyl thiophene, 2-methoxycarbonyl thiophene and3-ethoxycarbonyl thiophene; N-substituted amino thiophenes such as2-amino thiophene, 3-amino thiophene, 2-dimethylamino thiophene and3-dimethylamino thiophene; alkylhalothiophenes such as 4-chloro-3-butylthiophene and 4-methyl-2-chlorothiophene; alkoxyalkyl thiophenes such as2-methoxy-3-methyl thiophene, 2-methoxy-4-methyl thiophene and2-ethoxy-5-methyl thiophene; cyanochlorothiophenes such as3-chloro-2-cyanothiophene, 3-chloro-4-cyanothiophene,3-chloro-5-cyanothiophene, 4-chloro-2-cyanothiophene and4-chloro-3-cyanothiophene; nitrochlorophenes such as3-chloro-2-nitrothiophene, 3-chloro-4-nitrothiophene,3-chloro-5-nitrothiophene, 4-chloro-2-nitrothiophene and4-chloro-3-nitrothiophene; aminochlorothiophenes such as3-chloro-4-amino thiophene, 3-chloro-5-dimethyl amino thiophene,4-chloro-2-dimethyl amino thiophene and 4-chloro-3-dimethyl aminothiophene; carbamoyl chlorothiophenes such as 3-chloro-4-carbamoylthiophene, 3-chloro-5-dimethylcarbamoyl thiophene,4-chloro-2-dimethylcarbamoyl thiophene and 4-chloro-3-dimethylcarbamoylthiophene; halogenated alkyl halothiophenes such as4-chloro-2-trifluoromethyl thiophene and 4-chloro-3-trifluoromethylthiophene; benzothiophene; alkyl benzothiophenes such as 6-methylbenzothiophene, 4-methyl benzothiophene, 5-methyl benzothiophene,4-isopropyl benzothiophene, 2-isopropyl benzothiophene, 6-isopropylbenzothiophene, 3-isobutyl benzothiophene, 5,6-dimethyl benzothiophene,4-butyl-6-methyl benzothiophene, 2,5-dimethyl benzothiophene,3,4-diisopropyl benzothiophene, 4-isopropyl-5-methyl benzothiophene,4-butyl-6-isopropyl benzothiophene and 2-butyl-5-isopropylbenzothiophene; alkoxy benzothiophenes such as 4-methoxy benzothiophene,4-ethoxy benzothiophene, 5-butoxy benzothiophene, 6-isopropoxybenzothiophene, 5-methoxy benzothiophene, 6-ethoxy benzothiophene and2-methoxy benzothiophene; nitrobenzothiophenes such as4-nitrobenzothiophene and 5-nitrobenzothiophene; cyanobenzothiophenessuch as 4-cyanobenzothiophene and 5-cyanobenzothiophene;halobenzothiophenes such as 4-chlorobenzothiophene,5-chlorobenzothiophene, 6-chlorobenzothiophene and4-bromobenzothiophene; halogenated alkyl benzothiophenes such as4-trifluoromethyl benzothiophene and 5-trifluoromethyl benzothiophene;carbamoyl benzothiophenes such as 4-carbamoyl benzothiophene,5-dimethylcarbamoyl benzothiophene and 6-dimethylcarbamoylbenzothiophene; acyl benzothiophenes such as 4-acetyl benzothiophene,5-acetyl benzothiophene and 6-butanoyl benzothiophene; alkoxycarbonylbenzothiophenes such as 4-methoxycarbonyl benzothiophene,5-methoxycarbonyl benzothiophene and 6-ethoxycarbonyl benzothiophene;N-substituted amino benzothiophenes such as 4-amino benzothiophene,5-amino benzothiophene, 6-dimethylamino benzothiophene and4-dimethylamino benzothiophene; alkyl halobenzothiophenes such as4-chloro-5-butyl benzothiophene and 4-methyl-6-chlorobenzothiphene;alkoxyalkyl benzothiophenes such as 2-methoxy-4-methyl benzothiophene,2-methoxy-5-methyl benzothiophene and 2-ethoxy-5-methyl benzothiophene;halocyanobenzothiophenes such as 4-chloro-6-cyanobenzothiophene;pyrrole; halopyrroles such as 2-chloropyrrole, 3-chloropyrrole,4-chloropyrrole and 2-bromopyrrole; alkyl pyrroles such as 3-methylpyrrole, 4-methyl pyrrole, 5-methyl pyrrole, 3-isopropyl pyrrole,2-isopropyl pyrrole, 4-isopropyl pyrrole, 5-isopropyl pyrrole,2-isopropyl pyrrole, 3-isobutyl pyrrole, 3,4-dimethyl pyrrole,3-butyl-4-methyl pyrrole, 2,5-dimethyl pyrrole, 3,4-diisopropyl pyrrole,2-isopropyl-3-methyl pyrrole, 3-butyl-4-isopropyl pyrrole and2-butyl-5-isopropyl pyrrole; alkoxy pyrroles such as 3-methoxy pyrrole,2-ethoxy pyrrole, 3-butoxy pyrrole, 2-isopropoxy pyrrole, 2-methoxypyrrole, 3-ethoxy pyrrole and 2-methoxy pyrrole; nitropyrroles such as2-chloro-3-methoxy pyrrole, 2-chloro-4-methoxy pyrrole,2-chloro-5-ethoxy pyrrole, 3-nitropyrrole and 2-nitropyrrole;cyanopyrroles such as 3-cyanopyrrole and 2-cyanopyrrole; halogenatedpyrroles such as 3-chloropyrrole, 2-chloropyrrole, 3-bromopyrrole and2-bromopyrrole; halogenated alkyl pyrroles such as 3-trifluoromethylpyrrole and 2-trifluoromethyl pyrrole; carbamoyl pyrroles such as3-carbamoyl pyrrole, 2-dimethylcarbamoyl pyrrole and 4-dimethylcarbamoylpyrrole; acyl pyrroles such as 3-acetyl pyrrole, 2-acetyl pyrrole and3-butanoyl pyrrole; alkoxycarbonyl pyrroles such as 3-methoxycarbonylpyrrole, 2-methoxycarbonyl pyrrole and 3-ethoxycarbonyl pyrrole;N-substituted amino pyrroles such as 2-amino pyrrole, 3-amino pyrrole,2-dimethylamino pyrrole and 3-dimethylamino pyrrole; alkyl halopyrrolessuch as 4-chloro-3-butyl pyrrole and 4-methyl-2-chloropyrrole;alkoxyalkyl pyrroles such as 2-methoxy-3-methyl pyrrole,2-methoxy-4-methyl pyrrole and 2-ethoxy-5-methyl pyrrole;cyano-substituted chloropyrroles such as 3-chloro-2-cyanopyrrole,3-chloro-4-cyanopyrrole, 3-chloro-5-cyanopyrrole,4-chloro-2-cyanopyrrole and 4-chloro-3-cyanpyrrole; nitro-substitutedchloropyrroles such as 3-chloro-2-nitropyrrole, 3-chloro-4-nitropyrrole,3-chloro-5-nitropyrrole, 4-chloro-2-nitropyrrole and4-chloro-3-nitropyrrole; amino chloropyrroles such as 3-chloro-4-aminopyrrole, 3-chloro-5-dimethylamino pyrrole, 4-chloro-2-dimethylaminopyrrole and 4-chloro-3-dimethylamino pyrrole; carbamoyl chloropyrrolessuch as 3-chloro-4-carbamoyl pyrrole, 3-chloro-5-dimethylcarbamoylpyrrole, 4-chloro-2-dimethylcarbamoyl pyrrole and4-chloro-3-dimethylcarbamoyl pyrrole; halogenated alkyl halopyrrolessuch as 4-chloro-2-trifluoromethyl pyrrole and4-chloro-3-trifluoromethyl pyrrole; N-substituted pyrroles having, or anitrogen of the pyrrole ring of the aforementioned pyrroles, asubstituent such as an alkyl group such as a methyl, ethyl or benzylgroup, acyl group such as an acetyl, benzoyl or butanoyl group,substituted silyl group such as a t-butyldimethylsilyl or trimethylsilylgroup, or alkoxycarbonyl group such as a methoxycarbonyl orphenoxycarbonyl group; indole; alkyl indoles such as 6-methyl indole,4-methyl indole, 5-methyl indole, 4-isopropyl indole, 2-isopropylindole, 6-isopropyl indole, 3-isobutyl indole, 5,6-dimethyl indole,4-butyl-6-methyl indole, 2,5-dimethyl indole, 3,4-diisopropyl indole,4-isopropyl-5-methyl indole, 4-butyl-6-isopropyl indole and2-butyl-5-isopropyl indole; alkoxy indoles such as 4-methoxy indole,4-ethoxy indole, 5-butyoxy indole, 6-isopropoxy indole, 5-methoxyindole, 6-ethoxy indole and 2-methoxy indole; nitroindoles such as4-nitroindole and 5-nitroindole; cyanoindoles such as 4-cyanoindole and5-cyanoindole; haloindoles such as 4-chloroindole, 5-chloroindole,6-chloroindole and 4-bromoindole; halogenated alkyl indoles such as4-trifluoromethyl indole and 5-trifluoromethyl indole; carbamoyl indolessuch as 4-carbamoyl indole, 5-dimethylcarbamoyl indole and6-dimethylcarbamoyl indole; acyl indoles such as 4-acetyl indole,5-acetyl indole and 6-butanoyl indole; alkoxycarbonyl indoles such as4-methoxycarbonyl indole, 5-methoxycarbonyl indole and 6-ethoxycarbonylindole; N-substituted amino indoles such as 4-amino indole, 5-aminoindole, 6-dimethylamino indole and 4-dimethylamino indole; alkylhaloindoles such as 4-chloro-5-butyl indole and 4-methyl-6-chloroindole;alkoxyalkyl indoles such as 2-methoxy-4-methyl indole,2-methoxy-5-methyl indole and 2-ethoxy-5-methyl indole; halocyanoindolessuch as 4-chloro-6-cyanoindole; N-substituted indoles having, on anitrogen on the pyrrole ring of the aforementioned indoles, asubstituent such as an alkyl group such as a methyl, ethyl or benzylgroup, acyl group such as an acetyl, benzoyl or butanoyl group,substituted silyl group such as a t-butyldimethylsilyl or trimethylsilylgroup, or alkoxycarbonyl group such as a methoxycarbonyl orphenoxycarbonyl group; pyridine; alkyl pyridines such as 2-methylpyridine, 3-methyl pyridine, 2-ethyl pyridine, 3-isopropyl pyridine,2-isopropyl pyridine, 2-butyl pyridine, 3-butyl pyridine, 2-isobutylpyridine, 3-isobutyl pyridine, 3,4-dimethyl pyridine, 3-butyl-4-methylpyridine, 2,5-dimethyl pyridine, 3,4-diisopropyl pyridine,2-isopropyl-3-methyl pyridine, 3-butyl-4-isopropyl pyridine and2-butyl-5-isopropyl pyridine; alkoxy pyridines such as 3-methoxypyridine, 2-ethoxy pyridine, 3-butyoxy pyridine, 2-isopropoxy pyridine,2-methoxy pyridine and 3-ethoxy pyridine; nitropyridines such as3-nitropyridine and 2-nitropyridine; cyanopyridines such as3-cyanopyridine and 2-cyanopyridine; halopyridines such as2-chloropyridine, 3-chloropyridine, 4-chloropyridine and2-bromopyridine; halogenated alkyl pyridines such as 3-trifluoromethylpyridine and 2-trifluoromethyl pyridine; carbamoyl pyridines such as3-carbamoyl pyridine, 2-dimethylcarbamoyl pyridine and4-dimethylcarbamoyl pyridine; acyl pyridines such as 3-acetyl pyridine,2-acetyl pyridine and 3-butanoyl pyridine; alkoxycarbonyl pyridines suchas 3-methoxycarbonyl pyridine, 2-methoxycarbonyl pyridine and3-ethoxycarbonyl pyridine; N-substituted amino pyridines such as 2-aminopyridine, 3-amino pyridine, 2-dimethylamino pyridine and 3-dimethylaminopyridine; alkyl halopyridines such as 4-chloro-3-butyl pyridine and4-methyl-2-chloropyridine; alkoxyalkyl pyridines such as2-methoxy-3-methyl pyridine, 2-methoxy-4-methyl pyridine and2-ethoxy-5-methyl pyridine; cyano-substituted chloropyridines such as3-chloro-2-cyanopyridine, 3-chloro-4-cyanopyridine,3-chloro-5-cyanopyridine, 4-chloro-2-cyanopyridine and4-chloro-3-cyanopyridine; nitro-substituted chloropyridines such as3-chloro-2-nitropyridine, 3-chloro-4-nitropyridine,3-chloro-5-nitropyridine, 4-chloro-2-nitropyridine and4-chloro-3-nitropyridine; amino chloropyridines such as 3-chloro-4-aminopyridine, 3-chloro-5-dimethylamino pyridine, 4-chloro-2-dimethylaminopyridine and 4-chloro-3-dimethylamino pyridine; carbamoylchloropyridines such as 3-chloro-4-carbamoyl pyridine,3-chloro-5-dimethylcarbamoyl pyridine, 4-chloro-2-dimethylcarbamoylpyridine and 4-chloro-3-dimethylcarbamoyl pyridine; halogenated alkylhalopyridines such as 4-chloro-2-trifluoromethyl pyridine,4-chloro-3-trifluoromethyl pyridine; quinoline; alkyl quinolines such as6-methyl quinoline, 4-methyl quinoline, 5-methyl quinoline, 4-isopropylquinoline, 2-isopropyl quinoline, 6-isopropyl quinoline, 3-isobutylquinoline, 5,6-dimethyl quinoline, 4-butyl-6-methyl quinoline,2,5-dimethyl quinoline, 3,4-diisopropyl quinoline, 4-isopropyl-5-methylquinoline, 4-butyl-6-isopropyl quinoline and 2-butyl-5-isopropylquinoline; alkoxy quinolines such as 4-methoxy quinoline, 4-ethoxyquinoline, 5-butoxy quinoline, 6-isopropoxy quinoline, 5-methoxyquinoline, 6-ethoxy quinoline and 2-methoxy quinoline; nitroquinolinessuch as 4-nitroquinoline and 5-nitroquinoline; cyanoquinolines such as4-cyanoquinoline and 5-cyanoquinoline; haloquinolines such as4-chloroquinoline, 5-chloroquinoline, 6-chloroquinoline and4-bromoquinoline; halogenated alkyl quinolines such as 4-trifluoromethylquinoline and 5-trifluoromethyl quinoline; carbamoyl quinolines such as4-carbamoyl quinoline, 5-dimethylcarbamoyl quinoline and6-dimethylcarbamoyl quinoline; acyl quinolines such as 4-acetylquinoline, 5-acetyl quinoline and 6-butanoyl quinoline; alkoxycarbonylquinolines such as 4-methoxycarbonyl quinoline, 5-methoxycarbonylquinoline and 6-ethoxycarbonyl quinoline; N-substituted amino quinolinessuch as 4-amino quinoline, 5-amino quinoline, 6-dimethylamino quinolineand 4-dimethylamino quinoline; alkyl haloquinolines such as4-chloro-5-butyl quinoline and 4-methyl-6-chloroquinoline; alkoxyalkylquinolines such as 2-methoxy-4-methyl quinoline, 2-methoxy-5-methylquinoline and 2-ethoxy-5-methyl quinoline; halocyanoquinolines such as4-chloro-6-cyanoquinoline; and, imidazoles, triazoles, oxazoles,thiazoles, pyrazoles, isoxazoles, isothiazoles, pyrazines, pyrimidinesand pyridazines having substituents such as a hydrogen atom, linear orbranched C₁₋₈ alkyl group, linear or branched C₁₋₈ alkoxy group, nitrogroup, cyano group, halogenated C₁₋₈ alkyl group, halogen atom,carbamoyl group, C₁₋₈ acyl group, C₁₋₈ alkoxycarbonyl group orsubstituted or non-substituted amino group.

Although the iridium-containing catalyst used in the present inventionmay be any such catalyst provided it is a compound that contains iridium(Ir), the iridium-containing catalyst is preferably a catalystrepresented by the following general formula (X):IrABn  (X)composed of a cation portion represented by Ir, an anion portionrepresented by A and an alkene portion represented by B. Morepreferably, the anion portion represented by A is a chlorine atom,alkoxy group, hydroxyl group or phenyloxy group which may or may nothave a substituent, B is an alkene-containing compound such as COD(1,5-cyclooctadiene), COE (1-cyclooctene) or indene, and n is 1 or 2.Specific examples include IrCl(COD), IrCl(COE)₂, Ir(OMe)(COD),Ir(OH)(COD) and Ir(OPh)(COD). The amount used is 1/100000 to 1 mole, andpreferably 1/10000 mole to 1/10 mole, with respect tobis(pinacolate)diboron or pinacol borane.

Although there are no particular restrictions on the ligand in thepresent invention provided it is a Lewis base having the ability tocoordinate to an iridium-containing catalyst, it is preferably abidentate Lewis base compound, and more preferably, a compoundrepresented with the following general formula (XI) having a partialstructure of bipyridine which may or may not have a substituent:

(wherein, R⁶ and R⁷ may be the same or different and respectivelyrepresent a hydrogen atom, linear or branched C₁₋₈ alkyl group, linearor branched C₁₋₈ alkoxy group, nitro group, cyano group, halogenatedC₁₋₈ alkyl group, halogen atom, carbamoyl group, C₁₋₈ acyl group, C₁₋₈alkoxycarbonyl group or amino group which may or may not have asubstituent, or the following general formula (II) in which R⁶ and R⁷are substituted at position 6 and position 6′:

(wherein, R³ represents a hydrogen atom, linear or branched C₁₋₈ alkylgroup, linear or branched C₁₋₈ alkoxy group, nitro group, cyano group,halogenated C₁₋₈ alkyl group, halogen atom, carbamoyl group, C₁₋₈ acylgroup, C₁₋₈ alkoxycarbonyl group, or amino group which may or may nothave a substituent), specific examples of which include trialkylphosphines such as triphenyl phosphine and tributyl phosphine;ethylenediamines such as tetramethylethylenediamine and ethylenediamine;bipyridines such as 4,4′-di-t-butyl bipyridine, 2,2′-bipyridine,4,4′-di-methoxy bipyridine, 4,4′-bis(dimethylamino)bipyridine,4,4′-dichlorobipyridine and 4,4′-dinitrobipyridine, and1,10-phenanthroline, and preferable specific examples includingbipyridines such as 4,4′-di-t-butyl bipyridine, 2,2′-bipyridine,4,4′-di-methoxybipyridine, 4,4′-bis(dimethylamino)bipyridine,4,4′-dichlorobipyridine and 4,4′-dinitrobipyridine. The amount used is1/100000 mole to 1 mole, and preferably 1/10000 mole to 1/10 mole, withrespect to bis(pinacolate)diboron or pinacol borane.

Although the reaction of the present invention can be carried out in theabsence of solvent, a solvent can be used as is suitable. There are noparticular restrictions on the solvent used in the present inventionprovided it does not have an effect on the reaction, and examples ofsuch solvents include hydrocarbons such as octane, pentane, heptane andhexane; amides such as dimethylformamide and dimethylacetoamide;pyrrolidones such as N-methyl-2-pyrrolidone; ketones and sulfoxides suchas acetone, ethyl methyl ketone and dimethylsulfoxide; aromatichydrocarbons such as benzene, toluene, xylene and mesitylene; nitritessuch as acetonitrile; ethers such as diisopropyl ether, tetrahydrofuran,1,4-dioxane, 1,2-dimethoxyethane and anisole; and alcohols such asmethanol, ethanol, propanol, ethylene glycol and propylene glycol; withhydrocarbons such as octane, pentane, heptane and hexane beingpreferable. The reaction is carried out within a temperature range of 0to 180° C. and preferably 10 to 150° C.

Monoboronation and diboronation can be adjusted to a desired formationratio by suitably selecting the ratios used of the aforementionedaromatic heterocyclic compound (I) or (VII) and the aforementioned boroncompound represented by (III) or (IV). The formation ratio ofmonoboronation and diboronation change according to the ratio ofaromatic heterocyclic compound (I) or (VII) to boron compound (III) or(IV), and the greater aromatic heterocyclic compound (I) or (VII) isused in excess, the higher the priority of the occurrence ofmonoboronation. Normally, in the case of targeting monoboronation,2-fold to 100-fold moles, and preferably 2-fold to 50-fold moles, ofaromatic heterocyclic compound (I) or (VII) are used relative to theboron compound of (III) or (IV). In addition, in the case of targetingdiboronation, 1/100-fold moles to 2-fold moles, and preferably 1/10-foldmoles to 1.5-fold moles, of aromatic heterocyclic compound (I) or (VII)are used relative to the boron compound of (III) or (IV).

Although varying according to the amount of catalyst, a reactiontemperature and so forth, the reaction time is normally 0.2 to 120hours, and preferably 2 to 24 hours. In addition, the reaction ispreferably carried out in an inert gas atmosphere to preventdeactivation of the catalyst caused by oxygen during the reaction.Examples of inert gases include nitrogen gas and argon gas. In addition,although there are no particular restrictions on the reaction pressure,the reaction is normally carried out at atmospheric pressure.

Although target compounds of the present invention in the form ofaromatic heterocyclic boron compounds represented by general formulas(V), (VI), (VIII) and (IX) are obtained in this manner, ordinarypurification procedures can be carried out to improve purity, examplesof which include washing with saturated saltwater, concentration,precipitation, crystallization and distillation. In addition, theresulting target compounds can be treated with silica gel, alumina andso forth.

EXAMPLES

Although the following provides a more detailed explanation of thepresent invention based on its examples, the present invention is notlimited to only these examples.

Example 1 Synthesis of2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene

Bis(pinacolate)diboron (1 mmol), aromatic heterocyclic compound in theform of thiophene (10 mmol), catalyst in the form of IrCl (COD) (0.03mmol), ligand in the form of dtbpy (0.03 mmol) and 6 ml of octane weremixed followed by stirring while heating for 16 hours at 80° C. Afterallowing to cool to room temperature, the mixture was diluted withtoluene and washed with saturated saltwater. The organic layer wasconcentrated under reduced pressure followed by distilling off theresidue to obtain2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene at a yield of75%.

¹H-NMR (400 MHz, CDCl₃, TMS): δ 1.35 (s, 12H), 7.20 (dd, 1H, J=3.7 and4.6 Hz), 7.64 (d, 1H, J=4.6 Hz), 7.66 (d, 1H, J=3.4 Hz)

¹³C-NMR (100 MHz, CDCl₃, TMS): δ 24.75, 84.07, 128.21, 132.35, 137.14

MS m/e: 43(33), 110(50), 111(100), 124(82), 195(72), 210(M⁺, 96)

Exact mass calculated for C₁₀H₁₅BO₂S: 210.0886. found: 210.0881

Example 2 Synthesis of2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene

The same procedure as Example 1 was repeated with the exception of usingbpy instead of dtbpy for the ligand. The yield was 60%.

Example 3 Synthesis of2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene

The same procedure as Example 1 was repeated with the exception of usingIr(OMe)(COD) instead of IrCl(COD) for the catalyst, and allowing toreact for 4 hours at 25° C. The yield was 88%.

Example 4 Synthesis of2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene

The same procedure as Example 1 was repeated with the exception of usingIr(OH)(COD) instead of IrCl(COD) for the catalyst and allowing to reactfor 4 hours at 25° C. The yield was 86%.

Example 5 Synthesis of2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene

The same procedure as Example 1 was repeated with the exception of usingIr(OPh)(COD) instead of IrCl(COD) for the catalyst and allowing to reactfor 4 hours at 25° C. The yield was 82%.

Example 6 Synthesis of2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene

The same procedure as Example 1 was repeated with the exception of using1.0 mmol of pinacol borane instead of bis(pinacolate)diboron. The yieldwas 75%.

Example 7 Synthesis of2-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene

The same procedure as Example 1 was repeated with the exception of using2-methyl thiophene instead of thiophene for the aromatic heterocycliccompound. The yield was 85%.

¹H-NMR (400 MHz, CDCl₃, TMS): δ 1.33 (s, 12H), 2.53 (s, 3H), 6.84 (d,1H, J=3.4 Hz), 7.45 (d, 1H, J=3.4 Hz)

¹³C-NMR (100 MHz, CDCl₃, TMS): δ 15.36, 24.72, 83.85, 126.98, 137.62,147.52

MS m/e: 123(31), 124(76), 138(85), 209(49), 224(M⁺, 100)

Exact mass calculated for C₁₁H₁₇BO₂S: 224.1042. found: 224.1044

Example 8 Synthesis of(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)furan

The same procedure as Example 1 was repeated with the exception of usingfuran instead of thiophene for the aromatic heterocyclic compound. Theyield was 80% (2-position boronation/3-position boronation=92/8).

¹H-NMR (400 MHz, CDCl₃, TMS): δ (2-isomer) 1.35 (s, 12H), 6.45 (dd, 1H,J=1.7 and 3.4 Hz), 7.08 (d, 1H, J=3.4 Hz), 7.66 (d, 1H, J=1.4 Hz); δ(3-isomer) 1.32 (s, 12H), 6.59 (dd, 1H, J=0.7 and 1.7 Hz), 7.47 (t, 1H,J=1.5 Hz), 7.78 (m, 1H)

¹³C-NMR (100 MHz, CDCl₃, TMS): δ (2-isomer) 24.73, 84.20, 110.30,123.19, 141.31; (3-isomer) not observed

MS m/e: 43(33), 95(28), 109(31), 151(100), 179(29), 194(M⁺, 39)

Exact mass calculated for C₁₀H₁₅BO₃: 194.1114. found: 194.1122

Example 9 Synthesis of2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyrrole

The same procedure as Example 1 was repeated with the exception of usingpyrrole instead of thiophene for the aromatic heterocyclic compound. Theyield was 60%.

¹H-NMR (400 MHz, CDCl₃, TMS): δ 1.32 (s, 12H), 6.30 (ddd, 1H, J=2.3, 2.3and 3.4 Hz), 6.85 (ddd, 1H, J=1.2, 2.2 and 3.4 Hz), 7.00 (ddd, 1H,J=1.2, 2.4 and 2.4 Hz), 8.79 (br s, 1H)

¹³C-NMR (100 MHz, CDCl₃, TMS): δ 24.75, 83.56, 109.70, 119.99, 122.64

MS m/e: 107(49), 178(41), 193(M⁺, 100)

Example 10 Synthesis of(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine

The same procedure as Example 1 was repeated with the exception of using2 mmol of pyridine instead of thiophene for the aromatic heterocycliccompound. The yield was 60%.

¹H-NMR (400 MHz, CDCl₃, TMS): δ (4-isomer), (3-isomer);

¹³C-NMR (100 MHz, CDCl₃, TMS): δ (4-isomer), (3-isomer);

MS m/e: 105(32), 106(73), 119(100), 190(99), 205(M⁺, 90)

Exact mass calculated for C₁₁H₁₆BNO₂: 205.1274. found: 205.1265

Example 11 Synthesis of2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzo[b]thiophene

The same procedure as Example 1 was repeated with the exception of using4 mmol of benzothiophene instead of thiophene for the aromaticheterocyclic compound. The yield was 85%.

¹H-NMR (400 MHz, CDCl₃, TMS): δ 1.38 (s, 12H), 7.35 (ddd, 1H, J=1.7, 7.3and 8.8 Hz), 7.37 (ddd, 1H, J=1.8, 7.1 and 9.0 Hz), 7.85 (dd, 1H, J=2.2and 9.0 Hz), 7.89 (s, 1H), 7.91 (dd, 1H, J=1.5 and 9.0 Hz)

¹³C-NMR (100 MHz, CDCl₃, TMS): δ 24.80, 84.43, 122.51, 124.08, 124.36,125.29, 134.48, 140.43, 143.71

MS m/e: 160(80), 174(87), 259(25), 260(M⁺, 100)

Exact mass calculated for C₁₄H₁₇BO₂S: 260.1042. found: 260.1038

Example 12 Synthesis of2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzo[b]furan

The same procedure as Example 1 was repeated with the exception of using4 mmol of benzofuran instead of thiophene for the aromatic heterocycliccompound. The yield was 87% (2-position boronation/3-positionboronation=93/7).

¹H-NMR, (400 MHz, CDCl₃, TMS): δ (2-isomer) 1.39 (s, 12H), 7.23 (t, 1H,J=7.4 Hz), 7.34 (dt, 1H, J=1.2 and 7.8 Hz), 7.40 (s, 1H), 7.57 (d, 1H,J=8.5 Hz), 7.63 (d, 1H, J=7.8 Hz), (3-isomer) 1.37 (s, 12H), 7.26 (ddd,1H, J=1.8, 7.3 and 9.3 Hz), 7.29 (ddd, 1H, J=2.1, 7.3 and 9.5 Hz), 7.50(dd, 1H, J=2.4 and 6.6 Hz), 7.92 (dd, 1H, J=2.7 and 9.5 Hz), 7.92 (dd,1H, J=2.7 and 6.3 Hz), 7.95 (s, 1H)

¹³C-NMR (100 MHz, CDCl₃, TMS): δ (2-isomer) 24.77, 84.68, 111.97,119.53, 121.88, 122.71, 125.93, 127.48, 157.51; (3-isomer) not observed

MS m/e: 144(38), 158(25), 201(100), 244(M⁺, 72)

Exact mass calculated for C₁₄H₁₇BO₃: 244.1271. found: 244.1274

Example 13 Synthesis of2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)indole

The same procedure as Example 1 was repeated with the exception of using4 mmol of indole instead of thiophene for the aromatic heterocycliccompound. The yield was 89%.

¹H-NMR (400 MHz, CDCl₃, TMS): δ 1.36 (s, 12H), 7.09 (t, 1H, J=7.7 Hz),7.11 (s, 1H), 7.23 (t, 1H, J=8.3 Hz), 7.38 (d, 1H, J=8.3 Hz), 7.67 (d,1H, J=7.8 Hz), 8.56 (br s, 1H)

¹³C-NMR (100 MHz, CDCl₃, TMS): δ 24.81, 84.13, 111.24, 113.84, 119.77,121.58, 123.61, 128.27, 138.20

MS m/e: 143(35), 186(42), 242(27), 243(M⁺, 100)

Exact mass calculated for C₁₄H₁₈BNO₂: 243.1431. found: 243.1438

Example 14 Synthesis of3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1-(triisopropylsilyl)indole

The same procedure as Example 1 was repeated with the exception of using4 mmol of N-triisopropylsilyl indole instead of thiophene for thearomatic heterocyclic compound. The yield was 81%.

¹H-NMR (400 MHz, CDCl₃, TMS): δ 1.14 (d, 18H, J=7.6 Hz), 1.37 (s, 12H),1.74 (qq, 3H, J=7.6 and 7.6 Hz), 7.13 (ddd, 1H, J=1.8, 7.3 and 9.0 Hz),7.16 (ddd, 1H, J=1.5, 7.1 and 8.5 Hz), 7.50 (dd, 1H, J=2.3 and 6.5 Hz),7.67 (s, 1H), 8.06 (dd, 1H, J=2.8 and 6.2 Hz)

¹³C-NMR (100 MHz, CDCl₃, TMS): δ 12.73, 18.13, 24.96, 82.69, 113.71,120.41, 121.48, 122.36, 135.13, 141.19, 141.84

MS m/e: 230(28), 356(27), 399(M⁺, 100)

Exact mass calculated for C₂₃H₃₈BNO₂Si: 399.2764. found: 399.2766

Example 15 Synthesis of1-methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)indole

The same procedure as Example 1 was repeated with the exception of using4 mmol of N-methyl indole instead of thiophene for the aromaticheterocyclic compound. The yield was 64%.

Example 16 Synthesis of3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)quinoline

The same procedure as Example 1 was repeated with the exception of usingquinoline instead of thiophene for the aromatic heterocyclic compoundand reacting at 100° C. The yield was 81%.

¹H-NMR (400 MHz, CDCl₃, TMS): δ 1.40 (s, 12H), 7.57 (t, 1H, J=7.4 Hz),7.77 (t, 1H, J=7.7 Hz), 7.86 (d, 1H, J=8.1 Hz), 8.16 (d, 1H, J=8.1 Hz),8.66 (s, 1H), 9.21 (s, 1H)

¹³C-NMR (100 MHz, CDCl₃, TMS): δ 24.93, 84.35, 126.48, 127.58, 128.42,129.37, 130.54, 144.28, 149.45, 154.81

MS m/e: 155(89), 169(54), 198(37), 240(83), 255(M⁺, 100)

Exact mass calculated for C₁₅H₁₈BNO₂: 255.1430. found: 255.1427

Example 17 Synthesis of2,5-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene

Bis(pinacolate)diboron (1.1 mmol), thiophene (1.0 mmol), IrCl (COD)(0.03 mmol), dtbpy (0.03 mmol) and 6 ml of octane were mixed followed bystirring while heating for 16 hours at 80° C. After allowing to cool toroom temperature, the mixture was diluted with toluene and washed withsaturated saltwater. The organic layer was concentrated under reducedpressure followed by distilling off the residue to obtain 0.8 mmol of2,5-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene.

¹H-NMR (400 MHz, CDCl₃, TMS): δ 1.34 (s, 24H), 7.67 (s, 2H)

¹³C-NMR (100 MHz, CDCl₃, TMS): δ 24.74, 84.11, 137.66

MS m/e: 43(50), 59(27), 237(43), 250(100), 321(32), 336(M⁺, 55)

Exact mass calculated for C₁₆H₂₆B₂O₄S: 336.1738. found: 336.1750

Example 18 Synthesis ofbis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)furan

The same procedure as Example 15 was repeated with the exception ofusing furan instead of thiophene for the aromatic heterocyclic compound.The yield was 70% (2,5-position diboronation/2,4-positiondiboronation=88/12)

¹H-NMR (400 MHz, CDCl₃, TMS): δ (2,5-isomer) 1.33 (s, 24H) 7.06 (s, 2H),(2,4-isomer) δ 1.30 (s, 24H), 7.28 (s, 1H), 7.96 (s, 1H)

¹³C-NMR (100 MHz, CDCl₃, TMS): δ (2,5-isomer) 24.74, 84.23, 123.30(2,4-isomer) not observed

MS m/e: 83(27), 235(29), 276(47), 277(100), 305(30), 320(M⁺, 63)

Exact mass calculated for C₁₆H₂₆B₂O₅: 320.1966. found: 320.1962

Example 19 Synthesis of2,5-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyrrole

The same procedure as Example 15 was repeated with the exception ofusing pyrrole instead of thiophene for the aromatic heterocycliccompound. The yield was 79%.

¹H-NMR (400 MHz, CDCl₃, TMS): δ 1.31 (s, 24H), 6.83 (d, 2H, J=2.0 Hz),9.28 (br s, 1H)

¹³C-NMR (100 MHz, CDCl₃, TMS): δ 24.73, 83.71, 120.35

MS m/e: 234(29), 319(M⁺, 100)

Exact mass calculated for C₁₆H₂₇B₂NO₄: 319.2126. found: 319.2123

Example 20 Synthesis of2-methoxy-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene

The same procedure as Example 1 was repeated with the exception of using2-methoxy thiophene instead of thiophene for the aromatic heterocycliccompound. The yield was 82%.

Example 21 Synthesis of2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5-(trifluoromethyl)thiophene

The same procedure as Example 1 was repeated with the exception of using2-trifluoromethyl thiophene instead of thiophene for the aromaticheterocyclic compound. The yield was 82%.

Example 22 Synthesis of3-chloro-2-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)thiophene

The same procedure as Example 1 was repeated with the exception of using3-chloro-2-methyl thiophene instead of thiophene for the aromaticheterocyclic compound. The yield was 79%.

Example 23 Synthesis of3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1-(triisopropylsilyl)pyrrole

The same procedure as Example 1 was repeated with the exception of usingN-triisopropylsilyl pyrrole instead of thiophene for the aromaticheterocyclic compound. The yield was 77%.

¹H-NMR (400 MHz, CDCl₃, TMS): δ 1.09 (d, 18H, J=7.6 Hz), 1.32 (s, 12H),1.46 (qq, 3H, J=7.6 and 7.6 Hz), 6.62 (dd, 1H, J=1.2 and 2.4 Hz), 6.81(br t, 1H, J=2.8 Hz), 7.23 (br d, 1H, J=1.2 Hz)

¹³C-NMR (100 MHz, CDCl₃, TMS): δ 11.67, 17.81, 24.87, 82.71, 115.61,124.96, 133.67

MS m/e: 83(35), 223(51), 224(70), 348(30), 349(M⁺, 100)

Exact mass calculated for C₁₉H₃₆BNO₂Si: 349.2608. found: 349.2605

INDUSTRIAL APPLICABILITY

According to the production process of the present invention,monoboronation and diboronation can be adjusted to a desired ratio byregulating the ratios used of the aforementioned aromatic heterocycliccompound (I) or (VII) and the aforementioned boron compound representedby (III) or (IV). The present invention is an economical, simple andindustrially superior process capable of mono- or diboronating anaromatic heterocyclic compound at high yield, in a single step and undermild conditions.

1. A process of producing a heteroaryl boron compound of formula (VIII)or (IX):

wherein, u, v, w, R⁴ and R⁵ are the same as defined below, comprising:reacting an aromatic heterocyclic compound of formula (VII) with a boroncompound of formula (III) or (IV) in the presence of aniridium-containing catalyst of formula (X) and a ligand:

wherein u, v and w are each independently —CH═ or —N═, and R⁴ and R⁵ areeach independently a hydrogen atom, a linear or branched C₁₋₈ alkylgroup, a linear or branched C₁₋₈ alkoxy group, a nitro group, a cyanogroup, a halogenated C₁₋₈ alkyl group, a halogen atom, a carbamoylgroup, a C₁₋₈ acyl group, a C₁₋₈ alkoxycarbonyl group, an optionallysubstituted amino group, or formula (II) in which R⁴ and R⁵ are adjacentand form a ring:

wherein, R³ is a hydrogen atom, a linear or branched C₁₋₈ alkyl group, alinear or branched C₁₋₈ alkoxy group, a nitro group, a cyano group, ahalogenated C₁₋₈ alkyl group, a halogen atom, a carbamoyl group, a C₁₋₈acyl group, a C₁₋₈ alkoxycarbonyl group or an optionally substitutedamino group:

IrABn  (X): wherein, A is an anion portion and B is an alkene portion.2. The process according to claim 1, wherein A is a chlorine atom, alinear or branched C₁₋₈ alkoxy group, a hydroxyl group or a phenyloxygroup which may or may not have a substituent, B is 1,5-cyclooctadieneor 1-cyclooctene, and n is 1 or
 2. 3. The process according to claim 2,wherein A is a methoxy group, B is 1,5-cyclooctadiene and n is
 1. 4. Theprocess according to claim 2, wherein A is a chlorine atom, B is1,5-cyclooctadiene and n is
 1. 5. The process according to claim 2,wherein A of is a chlorine atom, B is 1-cyclooctene and n is
 2. 6. Theprocess according to claim 1, wherein, the ligand is of formula (XI):

wherein R⁶ and R⁷ are each independently, a hydrogen atom, a linear orbranched C₁₋₈ alkyl group, a linear or branched C₁₋₈ alkoxy group, anitro group, a cyano group, a halogenated C₁₋₈ alkyl group, a halogenatom, a carbamoyl group, a C₁₋₈ acyl group, a C₁₋₈ alkoxycarbonyl groupor an amino group which may or may not have a substituent, or of formula(II) wherein R⁶ and R⁷ are substituted at positions 3 and 3′:

wherein, R³ is a hydrogen atom, a linear or branched C₁₋₈ alkyl group, alinear or branched C₁₋₈ alkoxy group, a nitro group, a cyano group, ahalogenated C₁₋₈ alkyl group, a halogen atom, a carbamoyl group, a C₁₋₈acyl group, a C₁₋₈ alkoxycarbonyl group, or an amino group which may ormay not have a substituent.
 7. The process according to claim 6, whereinthe ligand is 2,2′-bipyridine.
 8. The process according to claim 6,wherein the ligand is 4,4′-di-tert-butyl-2,2′-bipyridine.
 9. The processaccording to claim 1, wherein the reaction is conducted in the presenceof a solvent.
 10. The process according to claim 9, wherein the solventis a hydrocarbon.
 11. The process according to claim 1, wherein areaction temperature is from 0 to 180°.
 12. The process according toclaim 1, wherein the boron compound is of formula (III) and a molarratio of the ligand to the boron compound is from 1/100,000 to 1/1. 13.The process according to claim 1, wherein a molar ratio of the compoundof formula (VII) to the compound of formula (III) or (IV) is from 2/1 to100/1.
 14. The process according to claim 1, wherein a molar ratio ofthe compound of formula (VII) to the compound of formula (III) or (IV)is from 1/100 to less than 2/1.
 15. The process according to claim 1,wherein the reaction is conducted in an inert gas atmosphere.